People with tuberous sclerosis complex (TSC) have a much higher than average prevalence of neurological problems such as seizures and learning disabilities. Clinicians and researchers have found that people with TSC are also prone to a wide range of mental health and behavioral problems. These include hyperactivity, attention deficit, sleep disturbances, anxiety, aggressiveness, autistic behaviors, and depression.
Nearly all people with TSC demonstrate at least one mental health complication, and many experience multiple, often overlapping symptoms. The severity of mental health manifestations also varies widely from one individual to another. While some individuals experience mild cases of attention deficit or sleep problems, severely affected individuals may demonstrate autistic behaviors, such as repetitive head movements, rocking, or self-stimulation, and in rare instances may inflict injuries upon themselves.
The impact that behavioral problems can have on the lives of people who exhibit them and their families can be profound. In some cases, they cause more daily concern and require more attention than do other aspects of TSC.
Although the high prevalence of behavioral problems is well documented among people with TSC, a clear causal explanation for this possible connection remains elusive. Because both learning disabilities and behavioral problems are relatively common in people with TSC who have experienced certain types of seizures, some specialists have suggested that seizures may cause disruptions in how the brain functions both cognitively and psychologically. In one study, researchers improved both cognitive and behavioral outcomes in a small number people with TSC by treating them as infants with a drug known to reduce or eliminate infantile spasms.
Other researchers have shown a positive correlation between the number of cortical tubers—or, more recently, the volume of brain space occupied by tubers—and both the severity of seizures and cognitive and behavioral impairment. This suggests that all three neurological manifestations—seizures, learning disabilities, and behavioral problems—may result from the same brain dysfunction.
The first step in successful treatment of mental health complications is accurate diagnosis. This is difficult in TSC for two reasons: The spectrum of issues associated with TSC is broad, and our understanding of how abnormalities in the brain cause these problems is limited. This has made it problematic for physicians to identify a clear course of treatment. Even so, some behavioral issues are highly treatable, while others still hold that promise.
Types of TSC-Related Behavioral Problems
Sleep disturbances, such as night waking, waking early, seizure-related sleep problems, and excessive daytime sleepiness, are some of the most common behavioral manifestations of TSC. These problems, which are sometimes caused by nighttime seizures, affect approximately 60 percent of people with TSC. Studies that monitored the nighttime electrical activity in the brains of people with TSC found that the majority experience many more awakenings and far less efficient sleep than do people without the disorder.
Attention Deficit Hyperactivity Disorder (ADHD)
Attention deficit disorder with or without hyperactivity is common in both adults and children with TSC. Twenty to 50 percent of people with TSC show signs of ADHD, compared with just 3 to 5 percent in the general population. This neurobehavioral disorder can make learning and social interactions difficult, even for those with normal cognitive abilities, by causing individuals to be easily distracted and frustrated, fidgety, impulsive, and forgetful. While the prevalence of ADHD is highest among individuals severely affected by TSC, including those with a high incidence of seizures, it is also much higher than average in people with TSC who have normal intelligence.
Aggressive outbursts and behaviors that cause self-injury are common among many people severely affected by TSC. Unfortunately, the causes of such behaviors remain unknown, and treatment success is variable. In general, aggressive behaviors tend to become less severe as a person grows older. However, they may be replaced by depression and anxiety.
People with TSC appear to experience higher rates of anxiety than do individuals without the disorder. The anxiety can be generalized, in the form of excessive worrying, or can be episodic, in the form of sudden, unexplained panic attacks. The effects of this disorder can be debilitating and tend to become more problematic with age.
Autism Spectrum Disorders
Autism remains one of the most mysterious of all neurobehavioral disorders. Decades of research have attempted to link autism to a wide variety of potential causes, but there still is no consensus. A possible explanation is that autism arises from a complex combination of factors. Interestingly, TSC is the medical condition most often associated with autism. For a relatively rare disorder, the prevalence of autism among people with TSC—estimates vary from 15 to 25 percent—is both statistically significant and troubling. Unfortunately, exact causes of autism and effective treatments of the disorder have yet to be identified.
Depression is common in people with TSC and often coexists or overlaps with other mental health problems such as anxiety. This coexistence often makes it difficult to accurately diagnose and treat mental health issues. For example, hyperactivity or aggression may actually result from irritability in a depressed child or adult. In other cases, depression may mask the underlying anxiety that often accompanies it. Fortunately there are many treatment options available for these symptoms, including supportive talk therapy and medications.